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How are fan coils controlled?

Views: 223     Author: Site Editor     Publish Time: 2022-12-12      Origin: Site

Central air conditioning is a very large system, which contains many syste-ms with different functions, one of which is the fan coil air conditioning system. What is the function of this system? It is a terminal device, that is, a component that directly handles the air. Without it, the air temperature cannot be flexibly changed.


Fan coil air conditioning system - working principle of fan coil system

This system includes two types of components, one is the fan coil unit, and the other is the cold and heat source supply system. Among them, there are not only one set of fan coil units, but several sets, so that they can be installed in several rooms Discretely, so that the whole house can enjoy the benefits of air conditioning.


2 Way Brass Actuator

2 Way Brass Actuator


Among them, the fan coil unit can be divided into multiple components, including fans, electric valves, MTD electric valves, coils, air filters, room temperature adjustment devices, boxes, etc.  Electric 2 way brass valve, electric 3 way brass valve, with L and T flow direction is widely usded in fan coil units.   


When these components are in operation, the fan circulates the air, and with the help of the coil, the air is heated or cooled, so that the indoor temperature can meet the corresponding requirements. If it is in summer, the fan will cool the air with the help of cold water in the coil to create a cool and comfortable environment; if it is in winter, then it needs the help of hot water in the coil to gradually heat the air and fill the room with heating.


When chilled water or hot water flows through the coil pipe, it exchanges heat with the air outside the pipe, so that the air is cooled, dehumidified or heated to adjust the indoor air parameters. It is a commonly used cooling and heating terminal device.


3 Way Brass Actuator

3 Way Brass Actuator


Fan coil unit is an ideal terminal product of central air-conditioning, and fan coil unit is widely used in hotels, office buildings, hospitals, commercial and residential buildings, and scientific research institutions.


It is understood that in order to meet the design and selection of different occasions, there are many types of fan coils, horizontal concealed (with return air box) fan coils, horizontal surface mounted fan coils, vertical concealed fan coils, vertical Surface mounted fan coil unit, cassette type two outlet fan coil unit, cassette type four outlet fan coil unit and wall mounted fan coil unit etc.


The selection of fan coil unit is a key issue. It is a common practice in the design of air-conditioning systems to select fan coil units according to the maximum cooling load of the air-conditioned room.


The purpose is to ensure the room temperature during peak load. In fact, most of the time when the air-conditioned room is running will not be at the peak load, which will cause excess cooling capacity, and switch to medium and low-level operation to reduce the cooling capacity output, thereby maintaining the thermal balance of the room.


When selecting a fan coil unit, in addition to the cooling capacity meeting the requirements of the calculated cooling load, it is also required to meet the matching of sensible heat and latent heat to meet the requirements of the room's heat-humidity ratio; the air volume must meet the temperature difference of the air supply, the number of air changes and the airflow organization Wait for usage requirement.


As the terminal equipment of the central air conditioner, the fan coil unit has a quality that determines the indoor air conditioning effect. At the same time, its cleaning problem also directly affects the use effect of the central air conditioner. There are a lot of dust particles in the atmosphere. Under the action of long-term pumping and returning air, the aluminum fins of the fan are full of dust and dirt.


At this time, on the one hand, the heat exchange between the chilled water and the hot air is affected and the air temperature drops; on the other hand, it also affects the sending of cold air that has been cooled after heat exchange, causing the phenomenon that the room is still not cold when the air conditioner is turned on.


Because the main engine of the central air conditioner sends 7-degree water into the fan coil unit after cooling, and after exchange in the fan coil unit, it becomes 15-16 degree cold air, which reduces the room temperature. Therefore, after the central air conditioner has been used for a period of time, it is necessary to clean the aluminum fins of the fan to solve the above disadvantages.


Fan coil plus fresh air system

1. Fan coil plus fresh air system: All the fresh air that is centrally processed is sent to the entrance of each room at a constant temperature and humidity, and then sent to each room after being heated or cooled again by the fan coil.

2. Fresh air system: Provide fresh air to meet people's requirements for air quality and dilute indoor pollution.

3. Do not bear or only bear part of the indoor load.

4. The number of fan revolutions in the fan coil unit and the electric control valve,electric actuators, electric modulating valve on the return water pipe of the coil unit are controlled by the temperature controller in the air-conditioned room, which can easily adjust the temperature of each room.